Sir_Kermit
2016-07-24 16:29:45
- #1
Hi,
However, the desired final temperature depends on the temperatures of cold/hot water and can be calculated using the mixing rule. Anyway, from an energy perspective, it initially does not matter how I achieve my desired temperature. It is primarily about the specific heat capacity of water and the required temperature differences for a desired amount (mass) of shower water. Example: I need 1 kg of water at 40 degrees and must raise the temperature by 30 degrees (assume the water supply temperature is 10 degrees). How I get there, with or without mixing, is always tied to the same amount of energy in joules, namely 30 x 4187 J. That is the bare theory, which you can test online with a mixing calculator.
For 1 kg of 40-degree warm water, you need 0.6 kg of water that you heat from 10 to 60 degrees and 0.4 kg of water at 10 degrees.
In the first case, it is 30 x 4187 joules; in the mixing case, it is 0.6 x 50 x 4187 joules.
What is not indifferent, however, are changes in efficiency (when starting the systems) and losses. But these depend heavily on the type of usage and the constructive design of the water supply in the house.
See the post by
Kermit
When the heated water is mixed down, there is also less flow through the hot water pipe.
However, the desired final temperature depends on the temperatures of cold/hot water and can be calculated using the mixing rule. Anyway, from an energy perspective, it initially does not matter how I achieve my desired temperature. It is primarily about the specific heat capacity of water and the required temperature differences for a desired amount (mass) of shower water. Example: I need 1 kg of water at 40 degrees and must raise the temperature by 30 degrees (assume the water supply temperature is 10 degrees). How I get there, with or without mixing, is always tied to the same amount of energy in joules, namely 30 x 4187 J. That is the bare theory, which you can test online with a mixing calculator.
For 1 kg of 40-degree warm water, you need 0.6 kg of water that you heat from 10 to 60 degrees and 0.4 kg of water at 10 degrees.
In the first case, it is 30 x 4187 joules; in the mixing case, it is 0.6 x 50 x 4187 joules.
What is not indifferent, however, are changes in efficiency (when starting the systems) and losses. But these depend heavily on the type of usage and the constructive design of the water supply in the house.
See the post by
Kermit